The QIAamp DNA Stool Mini Kit provides silica membrane-based purification of up to 30 μg genomic, bacterial, viral, and parasite DNA from fresh or frozen human stool or other sample types with high concentrations of PCR inhibitors. The combined action of InhibitEX, a unique adsorption resin, and an optimized buffer leads to removal of PCR inhibitors. The convenient QIAamp spin-column procedure provides purification in only 50 minutes. Purification of DNA using the QIAamp DNA Stool Mini Kit can be automated on theQIAcube.

The QIAamp DNA Stool Mini Kit is intended for molecular biology applications. This product is not intended for the diagnosis, prevention, or treatment of a disease.

QIAamp DNA Stool Mini procedure.

Removal of PCR inhibitors.

DNA was purified from 19 stool samples using [A] a conventional silica-based purification technique and [B] the QIAamp DNA Stool Mini Kit. To show whether inhibitors were present in the purified eluates, 5 µl of each eluate was added to PCR mixes with a template of 10 pg plasmid containing a GFP gene. Amplification of the GFP gene was successful in the presence of all QIAamp eluates whereas only 2 amplification reactions were successful in the presence of eluates prepared using the conventional technique containing the green fluorescent protein. M: markers; C: positive PCR control.

Performance

The QIAamp DNA Stool Mini Kit allows rapid purification of DNA from fresh or frozen human stool or other sample types with high concentrations of PCR inhibitors. Up to 220 mg stool can be processed routinely, and larger amounts can be processed with additional Buffer ASL. Typical yields of 10–30 µg are obtained in 50 minutes, and DNA is eluted in 200 µl. The purified DNA is sized up to 50 kb. DNA of this length denatures completely and has the highest amplification efficiency. Highly pure DNA is ready for direct use in downstream amplification reactions (see figure "Removal of PCR inhibitors").

DNA that has been purified using the QIAamp DNA Stool Mini Kit can be used in a wide range of downstream applications, including PCR and quantitative real-time PCR, infectious disease research, and screening.

Principle

DNA binds specifically to the QIAamp silica-gel membrane while contaminants pass through. No phenol–chloroform extraction is required. PCR inhibitors are removed by the combined action of InhibitEX, a unique adsorption resin, and an optimized buffer. Rigorous lysis using proteinase K ensures high yields of all types of DNA common in stool, including colorectal epithelial cells, bacteria, viruses and other gastrointestinal pathogens.

The protocol describes the preservation and concentration of stool samples (in preparation for microscopic examination for intestinal parasites), using two systems from Meridian Biosciences, followed by isolation of DNA from the stool samples for pathogen detection using the QIAamp DNA Stool Mini Kit.